Studies on Protective Coating IX

Polymers of vinylpyridine and of its derivatives and copolymers of vinylpyridine with other series of vinyl compounds were experimentally synthesized. The purpose of the synthesis was to obtain such protective coating agents exhibiting protective activity on drugs and solubility in gastric juice. Solubility, water vapor permeability through the film, and viscoelasticity were tested for each compound. The practical coatings on tablets were also carried out and disintegration time of coated tablets and shelf life of active ingredients were subsequently investigated. All the compounds showed excellent properties as protective coating agents.